Rock drill



April 6, 1937. 'w. A. SMITH, SR 2,076,355

- ROCK DRILL Filed Feb. 28, 1936 INVENTOR.

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.HLS' ATTORN Patented Apr. 6, 1937 ROCK DRILL William A. Smith, Sr., Athens, Pa., assignor to Ingersoll-Rand Company, Jersey City, N. J., a corporation of New Jersey Application February 28, 1936, Serial No. 66,175

5 Claims.

This invention relates to rock drills, and more particularly to a back end construction for rock drills of the type embodying automatic rotation mechanism and devices for flushing the drill hole.

One object of the invention is to maintain the length and weight of the rock drill to a minimum.

Another object is to conveniently arrange the manually operable controlling valves with respect to each other on one side of the back casing portion of the drill so that each may be readily accessible and the conduits leading thereto may hang suspended in separate transverse planes.

Other objects will be in part obvious and in part pointed out hereinafter.

In the accompanying drawing and in which similar reference numerals refer to similar parts,

Figure l is an elevation, in section, of so much of a rock drill as will serve to illustrate the in-- vention, and

Figure 2 is a transverse View taken through Figure 1 on the line 22 looking in the direction indicated by the arrows.

Referring more particularly to the drawing, 20 designates in general, a rock drill comprising a 5 cylinder 2| which is bored to provide a piston chamber 22 for the accommodation of a reciprocatoryhammer piston 23. The cylinder 2| has a free exhaust port 24 which is controlled by the piston 23, and a closure is provided for the front end of the piston chamber by a washer 25 which also serves as a guide for an extension 26 on the piston 23.

In the rear portion of the cylinder 2| is an enlarged bore 21 containing valve mechanism 28 whereby the distribution of pressure fluid to the ends of the piston chamber 22, for actuating the piston 23, is effected. The valve mechanism 28 comprises, in the present instance, a pair of plates 29 and 39. The plate 29 forms a closure for the rear end of the piston chamber 22 and serves as a seating surface for a valve 3|, of the oscillatory plate type, which controls inlet passages 32 and 33 leading to the rear and front ends, respectively, of the piston chamber.

The rear end of the plate preferably projects a slight distance beyond the end of the cylinder 2|, and on the forward portion of the plate 30 is a cylindrical extension 34 which extends through the valve 3| and into the plate 29. The plates 29 and 30 are suitably recessed to provide a chamber 35 for the valve 3|, and said plates may be conveniently held against rotative movement with respect to the cylinder 2| by a pin 36 partly embedded in the plates and in the cylinder.

The plates 30 and 29 are held securely against endwise movement by a back head 31 constituting the rearmost casing part of the rock drill. The back head may be secured to the cylinder 2| in any convenient manner, as for instance by the usual side rods (not shown).

In the form illustrated the back head 31 is provided with a tapered recess 33 for the accom; modation of rotation mechanism comprising a' ratchet ring 39 and the usual rifle bar 40 for effecting rotary movement of the piston 23 and thus, through well known devices, a working implement (not shown) which the piston is intended to actuate.

The rifle bar 40 extends through the plate 30 and its extension 34 and into the piston 23, wherewith it may be interlocked, and carries at its rear end a head 4| which lies within the ratchet ring 39. The head 4| carries the usual spring-pressed pawls 42 adapted to engage the ratchet teeth 43 on the inner surface of the ratchet ring to hold the rifle bar stationary during the rearward stroke of the piston and thereby causes the piston to describe a partial revolution.

The ratchet ring 39 is tapered exteriorly to conform with the taper of the recess 38. However, the diameter of corresponding sections of the ratchet ring and the recess 38 differ slightly, that of the ratchet ring being slightly larger in order to enable the ratchet ring to be press fitted in the recess 38 to secure it immovably therein. The ratchet ring may be additionally held against rotational movement within the back head 31, as by the pin 36 employed for anchoring the plates 29 and 30 in the cylinder 2|,

In the assembled position of the back head 3'1 and the rotation mechanism the ratchet ring 39 seats directly upon the plate 30 so that when the back head is clamped in position the plates 36 and 29 will also be clamped securely against endwise movement in the recess 21.

In the periphery of the ratchet ring is an annular recess 44 which serves as a supply chamber for pressure fluid and communicates with the valve chamber 35 through supply passages 45 in the ratchet ring and the plate 30. In the same transverse plane as the recess 44 is a throttle valve 46 which controls the admission of pressure fluid into the recess 44. The throttle valve 46 is illus trated as being of the rotary type having a central chamber 41 which may be in constant communication with a source of pressure fluid supply through a flexible conduit (not shown). In the wall of the throttle valve 46 is a port 48 which is adapted to register directly with the recess 44, the

throttle valve 46 being located immediately adjacent the ratchet ring 39.

n the same side of the back head 31 as the throttle valve 46 and at a point rearwardly of 5 the ratchet ring 39 is a second valve 49 employed for controlling the admission of cleansing liquid into the drill. The throttle valve 49 is also of the rotary type and may have connected thereto, as by means of a freely swinging connection, a hose (not shown) for introducing liquid into the interior of the throttle valve 49 whence it may flow, in the open position of the throttle valve, through a port 50 in the throttle valve and a passage 5| to a water tube 52 extending through the rock drill for supplying water to the working implement.

The water tube 52 may be securely held in position by a plug 53 threaded into the rear end of the back head and having a portion of the passage 5l extending therethrough.

From the foregoing description it will be readily apparent that by disposing the throttle valve 46 on the forward portion instead of the rearward end of the back head, as has, been customary heretofore, that portion of the back head lying rearwardly of the rotation mechanism may be materially shortened and the overall length and weight of the drill will be advantageously reduced. Moreover, by thus arranging the valve 46 the water valve 49 may also be placed on the same side of the rock drill as the valve 45 and both valves will, therefore, be located within convenient reach of the operator.

A further desirable advantage of this construction is that in a drill of the drifter type the conduits through which pressure fluid and cleansing liquid are conveyed to the drill may hang suspended in different transverse planes and without risk of becoming entangled with each other as they often do in structures where the valves are located on opposite sides of the water connection 53.

I claim:

1. In a back end construction for rock drills, the combination of a casing and a piston therein,

rotation mechanism in the casing for rotating the piston comprising a ratchet ring, a supply chamber for pressure fluid in the periphery of the ratchet ring, means for introducing pressure fluid into the supply chamber, and an outlet passage for the supply chamber.

2. In a back end construction for rock drills, the combination of a casing and a piston therein, rotation mechanism in the casing for rotating the piston comprising a ratchet ring having a recess forming a supply chamber, a throttle valve adjacent the ratchet ring having a port adapted to register directly with the supply chamber, and an outlet passage for the supply chamber.

3. In a back end construction for rock drills, the combination of a casing and a piston therein, rotation mechanism in the casing for rotating the piston comprising a ratchet ring having a pressfit in the casing, an annular supply chamber in the periphery of the ratchet ring, a throttle valve in the same transverse plane as the ratchet ring and having a port opening directly into the supply chamber, and an outlet passage for the supply chamber.

4. In a back end construction for rock drills, the combination of a casing and a piston in the casing, a tapered bore in the casing, rotation mechanism for rotating the piston comprising a ratchet ring having a tapered surface and being press-fitted into the tapered bore, an annular supply chamber in the periphery of the ratchet ring, a throttle valve having a port to register directly with the supply chamber, and an outlet passage for the supply chamber.

5. In a back end construction for rock drills, the combination of a casing and a piston therein, rotation mechanism for rotating the piston comprising a ratchet ring having a supply chamber for pressure fluid, valve mechanism for efiecting the distribution of pressure fluid in the rock drill, means for conveyng cleansing liquid through the rock drill, a back head, a throttle valve on one side of the back head for controlling the flow of pressure fluid to the valve mechanism and having a port adapted to register with the supply chamber, and a throttle valve in the same side of the back head as the first said throttle valve for controlling the flow of cleansing liquid to the said means.

WILLIAM A. SMITH, SR. 

